Sometimes a great pitching performance is about spreading excellence over an entire season. Pedro Martinez, for instance, produced arguably the two best pitching seasons of all time, in 1999 and 2000, by consistently overwhelming hitters over the span of months and even years.1 His dominance could certainly be glimpsed in specific moments as well, but the magnitude of Martinez’s accomplishments is best described with broad numbers (for example, he has the lowest single-season ERA, relative to the league, in major league history).
For others, though, pitching greatness manifests itself in far shorter sequences. When Orel Hershiser unanimously won the 1988 National League Cy Young, it was more about his 59 consecutive scoreless innings — which broke fellow Dodger Don Drysdale’s then-20-year-old major league record — than his season-long numbers. Although Hershiser tied Cincinnati’s Danny Jackson for the NL lead in wins, he wasn’t No. 1 in winning percentage or ERA — to say nothing of newer metrics such as fielding independent pitching (FIP), on which he lagged well behind league leaders.2
That year, Hershiser’s historic streak meant more than performance over the season as a whole. And the same thing might be playing out in the NL this season. With eight scoreless innings Sunday against the Nationals, another Dodger, Zack Greinke, has extended his own scoreless streak to 43⅔ innings. Greinke is one of the best pitchers in the game, but just like Hershiser, he’s being oversold by The Streak.
Greinke leads the majors in ERA with a microscopic 1.30, but he’s also been the beneficiary of good fortune. Similar to Hershiser, almost half the wins generated by LA’s run-prevention corps with Greinke on the mound can be attributed to factors outside his own pitching skill. Take those wins away, and Greinke has been only the sixth-best pitcher in baseball this season. (He ranks fourth even if we just look at the past 30 days.)
During Greinke’s streak, his fielders have converted into outs 82.4 percent of the balls he allowed to be put in play, a far greater rate than the league average of 70.6 percent. And it doesn’t seem to be possible to produce a historic consecutive-innings streak without benefiting from that kind of defense (and luck). Behind Hershiser, 81.4 percent of the balls in play were turned into outs, and for Drysdale, the rate was 81.6 percent.
We can debate whether Greinke’s pursuit of the streak is easier or harder than Hershiser’s or Drysdale’s was. Greinke has had to throw more pitches per inning,3 but he has also spread his innings over a greater number of starts, which has allowed him to benefit from a reduced “times through the order” penalty. The bigger takeaway, however, is that these kinds of streaks — even those of the 59-inning variety — cover only a few starts, too small a sample for us to easily untangle the effects of luck and skill.
Streaks are nothing if not one of baseball’s favorite preoccupations, but they also take a fundamentally long-term game and focus it on the short term. Joe DiMaggio won the 1941 AL MVP in large part because he hit safely in 56 straight games, but Ted Williams was easily the better player over the entire season.4 Hershiser won the Cy Young but probably wasn’t the NL’s best pitcher in 1988. And Greinke’s streak, impressive and exciting as it is, shouldn’t obscure the other fantastic pitching seasons we’re seeing across MLB this year.